GWR, the UK radio group embarking on a merger with rival Capital Radio, said it had grown underlying first-half profits despite warning of weakness in advertising markets.

The company, which owns 36 local stations across the UK and the country’s largest commercial radio channel Classic FM, said pre-tax profits for the six months to September 30 excluding discontinued businesses, goodwill amortisation and exceptional items rose 12 per cent to £6.9m ($12.8m).